An imaging integrated circuit (IC) uses a pixel circuit array to collect image information from a target scene. For example, an imaging pixel circuit array in an optical mouse can collect image information for motion estimation from a surface on which the optical mouse is manipulated. The pixel circuit array includes a number of pixel circuits, in which each pixel circuit collects a separate image signal sample. The image signal samples that are collected by the pixel circuits have to be transferred from individual pixel circuits to a back-end signal processor for processing.
The process of collecting image signal samples using pixel circuits and transferring the image signal samples from the pixel circuits to a back-end signal processor creates challenges in designing an imaging IC, such as power detection threshold, image lag, power dissipation, and frame rate.